Crane



Dec. 29, 1953 N. G. BELL CRANE Filed Nov. 16, 1950 Inventor ,4 4 04 2 60/V/Vf Bf! L,

- ies. 1i! a a Patented Dec. 29, 1953 UNITED STATES PATENT. OFFICE CRANE Noel Gonne Bell, London, England Application November 16, 1950, Serial No. 195,986

1 Claim.

This invention relates to mobile cranes of the type comprising a base, a turntable supported on the base, and a jib, a mast with a backtie, and an engine mounted on the table. By the term mobile crane I mean a crane equipped with wheels or crawler tracks or walking traction mechanism or the like.

The invention provides an improved crane of this type characterised in that the turntable is made in two parts detachably jointed together adjacent the rear point of support on the base, and in that an additional member is provided which connects the table joint to the top junction of the mast and the backtie, the arrangement being such that the crane may be easily dismantled for transport. The arrangement may be such that a part of the dismantled crane may serve as a temporary derrick for the erection or dismantling of the remainder.

The invention will be clearly understood from g the following description aided by the accompanying drawing which shows, by way of example, a crawler-track crane and a rail-wheeled crane embodying constructional forms of the invention.

Fig. 1 of the drawing is a side elevation of the crawler-track crane.

Fig. 2 is a plan corresponding to Fig. 1.

Fig. 3 represents on a larger scale a section, in the plane IIIIII of Fig. 4, of the connection of the crawler-track frame to the axle, the section being in a plane transverse to the crane of Fig. 1.

Fig. 4 is an elevation in the plane IV-IV of Fig. 3.

Fig. 5 is a side elevation showing the rear part of the crane of Figs. 1 and 2 adapted for use as an erection derrick.

Fig. 6 is a side elevation of the rail-wheeled crane.

The crane illustrated by Figs. 1 and 2 comprises a base I on a pair of endless or crawler-tracks 2 supporting a turntable 3, 4 on which are mounted a lattice jib 5, an A-frame front mast 6, an additional or centre A-frame mast I, an A-frame backtie 8, and an engine 9. The jib 5 and front mast 6 are hinged at their lower ends to the front part 3 of the turntable, and the top of the jib 5 is connected to the top of the front mast 6 by a derricking rope Ill. The engine 9 is mounted on the rear part 4 of the turntable which part is connected to the top of the front mast 6 by the backtie 8.

The two parts 3 and 4 of the turntable are jointed together at H just behind the turntable rear supporting wheels or rollers, and the additional or centre mast 1 connects this joint II to the top junction of the front mast Ii and the backtie 8.

The engine 9 has drums l2 and I3 for the derricking rope I 0 and for a hoisting rope l4; if required it may have additional drums for other purposes. The travelling and revolving mechanism. of the usual type, in the base and front portion of the turntable, are driven from the engine either directly by chain or through the intermediary of a shaft in the joint i I of the turntable.

As shown in Figs. 3 and 4 the crawler-track frames 2 are detachable from the base I the ends of the axles l5 of the latter being bevelled on the top or side and fitting into apertures IS in the frames 2 having corresponding bevels thereby affording a rigid and easily made connection when the ends of the axles l5 are wedged into the aperture l6 and locked outside as by means of wedges l7.

Fig. 5 shows how part of the described crane, consisting of the rear portion 4 of the turntable with the engine 9 thereon together with the centre mast 1, the backtie 8 and the front mast 6 converted for use as a jib, may serve as a temporary derrick for erecting or dismantling and loading the remainder of the crane. This derrick-constituting part of the crane may be mounted as a unit on a transport vehicle l8 by backing the said vehicle under the rear part 4 of the turntable before dismantling the crane. In the case of a very heavy crane, the said unit may be mounted on temporary staging.

Dismantling may proceed as follows: The crane is run on to a blocking 26 to raise the turntable 3, 4 to the same level as the floor of a transport vehicle l8 (Fig. 5). The jib i is lowered on to another transport vehicle (not shown) and disconnected, and the rear part 4 of the turntable with the engine 9, the centre mast 1, and the backtie 8 thereon are rolled on to the transport vehicle I8; and the front mast 6 is fitted as a temporary jib. The base I is then raised with a jack 2! to allow the crawler track units 2 to be disconnected and loaded by the temporary derrick on to the second mentioned transport vehicle, and the base I is finally loaded on to a third transport vehicle.

The crane of Fig. 6 is generally similar to that already described but is mounted on wheels l9 running on a rail track 20. In this case the base 2| supporting the two-part turntable 3, 4 is larger and is made in convenient sections for transport. An additional hoisting drum 22 and a drum 23 for slewing by cable 24 round slewing circle 25 in known manner are provided on the front part 3 of the turntable. These drums are driven by a chain drive from the engine.

A crane in accordance with the invention is constructed so that it may be dismantled into convenient units whose width, length and weight are within the limits of normal road transport regulations or, in the case of large cranes, within the limits allowed with special restrictions. The

turntable can be made longer than usual and thereby the engine can be placed well to the rear, approaching the limiting position for backward stability of the crane, and so increase load lifting capacity; at the same time theengine attached to the rear part of the .turntablemay form one unit for transport.

A crane constructed as herein described-may be easily erected and dismantled by its own power without the use of an 'aux-iliarycrane.

Acrane as herein described can be used-asan excavatorvor for any of the other purposes known per se.

1 claim:

A mobile crane comprising, in combination-a base, a table supported on the said base, the said table being constituted by a front part and a rear part jointed together adjacent the rear point of the said support, a jib and a front mast mounted on the front part of the said table, a backtie and an engine together with at least one drum mounted on the rear part of the said table, and a centre mast connecting the said table joint with the top junction of the said front mast and baoktie, whereby the said rear. part'of the table along with the said engine and drum, centre mast and backtie and front mast may serve as a temporary derrick, the said front mast for this purpose being detached from its normal position and its lower end being pivotally mounted at the footof the centre mast to constitute a jib.

NOEL GONNE BELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 978,553 Brorberg Dec. 13, 1910 1,289,427 Ferris Dec. 31, 1918 1,980,297 Scott Nov. 13, 1934 2,139,960 Kauffman Dec. 13, 1938 

